Ariston Hotpoint AQGF – F-02 error

Hello,

My Ariston Hotpoint AQGF 149 has been displaying a f-02 error code for the past few days.

What happens is the following :
The program starts, and water fills up. The motor tries to make the tub turn, but only rotates by a few degrees, producing a clunk noise. This goes on for a few minutes, at which point :
* Either the machine displays an f-02 error, empties itself, and releases the door lock. If I want to run the machine again, I need to unplug it for a minute or so and back again.
* Or the machine goes on to the next cycle (probably the wash cycle compared to the previous “soak” (?) cycle). At which point the tub actually rotates normally and even goes through the spinning cycle and the whole program.

I’ve done some research and saw that :
* The brushes could be defective, however that’s a tri phase motor (ACC 20585.118) so no brushes. Anyway the motor turns well during spinning.
* The tachometer could have fallen off, however it’s part of the motor and I haven’t found a spare part. Anyway the motor turns well during spinning.
* There’s a power module (?) managing the various cycles, so could that be the faulty part? Is it possible that a “path” of the module (the one sending the correct amount of power for a soak cycle for instance) is broken while the others work fine? Can that even be repaired (without changing the card itself)?

On a side note, I’ve tried to run an spin cycle with no load in the tub, with the same behavior as previously described.
Funny thing is that when the spin cycle is selected on the dial, the machine switches sporadically between the delicate and heavy spin programs on the display (800 to 1200 rpm, and duration). Could that indicate that the module is the glitchy part?

Thanks in advance for your help!